I have around 130gb of movies on an external drive. It would be nice to copy most of these to a micro SD card to have on my phone when I'm stuck on a train or something. I couldn't find one either so got stuck with a 64gb. That said, 128gb and even 256gb SD cards are out there. They are super expensive tho apart from a couple of manufacturers with varying reviews.

I have around 130gb of movies on an external drive. It would be nice to copy most of these to a micro SD card to have on my phone when I'm stuck on a train or something. I couldn't find one either so got stuck with a 64gb. That said, 128gb and even 256gb SD cards are out there. They are super expensive tho apart from a couple of manufacturers with varying reviews.
You could get two 64GB cards. I know it's not quite as practical as a straight 128GB of storage, but it's possible to buy now and not too expensive. Orrr, you could get a 128GB flash drive, USB OTG isn't so much of a practicality issue when the phone would be set down in front of you to watch a film.

A 128gb Micro-SD card is coming out sometime soon, it's started showing up in some online stores. See here for more info.
They'll be hideously expensive, no doubt. It'll be over a year until they're of any use to those who don't just excrete money.

my bet is SanDisk will announce a 128GB microSDXC by end September in time for the Holidays as it has was Sep 2011 when the 64GB microSDXC was announced and max capacities double every 18 - 24 months max. SanDisk made a press release in March that shows that the underlying memory technology needed for a 128GB microSDXC is now in production sampling (they didn't expressly say microSD though, because there are other factors).